// Based on http://bl.ocks.org/900762 by John Firebaugh

d3.json("../data/faithful.json", function(faithful) {

data = faithful;

var width = 800,

height = 400;

var x = d3.scale.linear()

.domain([30, 110]).range([0, width]);

var y = d3.scale.linear()

.domain([0, .1])

.range([0, height]);

var bins = d3.layout.histogram().frequency(false).bins(x.ticks(60))(data),

max = d3.max(bins, function(d) { return d.y; });

var kde = science.stats.kde()

.sample(data);

var vis = d3.select("body")

.append("svg")

.attr("width", width)

.attr("height", height);

var bars = vis.selectAll("g.bar")

.data(bins)

.enter().append("g")

.attr("class", "bar")

.attr("transform", function(d, i) {

return "translate(" + x(d.x) + "," + (height - y(d.y)) + ")";

});

bars.append("rect")

.attr("fill", "steelblue")

.attr("width", function(d) { return x(d.dx + 30) - 1; })

.attr("height", function(d) { return y(d.y); });

var line = d3.svg.line()

.x(function(d) { return x(d[0]); })

.y(function(d) { return height - y(d[1]); });

vis.selectAll("path")

.data(d3.values(science.stats.bandwidth))

.enter().append("path")

.attr("d", function(h) {

return line(kde.bandwidth(h)(d3.range(30, 110, .1)));

});

});